42 
M. G. Sykes. 
The sporangium dehisces by a longitudinal slit, along a line of cells 
which constitute a more or less definite annulus, 1 the position of 
which varies in the different species. 2 The wall of the sporangium 
is composed of two or more layers of cells, which generally increase 
in number towards the base of the sporangium, and a tapetum. The 
cells of the outer layer have their walls lignified in unequal strips. 
In a radial section of the cone the sporangium is a simple oval in 
shape, but in a section tangential to the axis, the sporangium is 
much elongated and is usually described as ” saddle-shaped.” 
II.— Genus I. Phylloglossum. 
The cones of this genus have already been discribed by Bower. 3 
It is only necessary to remark here that the sporophylls differ 
slightly from the vegetative leaves, and that they are aggregated to 
form a definite cone. Each sporophyll is short and simple, rather 
thick, with incurved edges and a very short dorsal out-growth 
(Text-fig. 3) which partly protect the sporangium. 4 It strongly 
Text-fig. 3. Longitudinal section of sporophyll of Phylloglossum ; shewing 
axillary sporangium. F., Small dorsal flap of sporophyll. B., Lignified cells 
in sporangium pedicel. 
resembles that of L. dalhonsianum (PI. II., Fig. 4b), also, more 
remotely, that of L. inundatum, (Text-fig. 5). The sporangium 
arises in the axil of the sporophyll, but does not fit closely into the 
base of the sporophyll immediately above ; a considerable portion 
of the sporangium is thus left exposed. Dehiscence of the 
sporangium takes place by an apical longitudinal slit. 
A longitudinal section (Text-fig. 3) shews that the sporangium 
is borne on a short stalk in which a few cells with slightly lignified 
walls are often present. 
1 Goebel, Organography, II., p. 579, and cf. Smith, 1900. 
2 Engler and Prantl, Teil I., Abt. 3, pp. 586 and 587. 
3 Bower, 1885. 
4 cf. Engler and Prantl, Teil I., Abt. 3, p. 576, Fig. 362 c. 
